This invention relates generally to a cable stayed bridge, and more particularly to such bridge having box edge beams to which the cable stays are connected.
A known cable stayed bridge construction may include longitudinal I-beams located at the underside of a reinforced concrete deck adjacent opposite sides of the deck, spaced apart transverse floor beams underlying the deck and joined at opposite ends to the longitudinal I-beams, cable stays anchored to selected floor beams for supporting the deck structure from the pylons, and crash barrier walls provided on the upper surface of the deck inwardly of the cable stays.
There is the need to improve upon such a cable stayed bridge construction in a number of ways. For example, the bridge could be improved, especially for long spans, to enhance longitudinal and torsional rigidity and to withstand the forces of strong wind. Options should be available for longitudinal side beams other than steel, such as reinforced concrete or a composite of concrete and steel. Improved resistance to buckling needs to be devised, and aerodynamic stability of the bridge would offer a much improved resistance to wind. The bridge structure should allow for convenient and effective placement, stressing, adjustment and replacement of the cable stays without compromising bridge rigidity. And, compensation should be made for long-term concrete strains due to shrinkage and creep, while at the same time compensating for long-term stress to which the steel structural beams are subjected. An improved method of bridge construction for efficiency and economy, is also desirable.